Complex classes like CMB2_Utils often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use CMB2_Utils, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 13 | class CMB2_Utils { | 
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| 14 | |||
| 15 | /**  | 
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| 16 | * The WordPress ABSPATH constant.  | 
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| 17 | * @var string  | 
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| 18 | * @since 2.2.3  | 
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| 19 | */  | 
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| 20 | protected static $ABSPATH = ABSPATH;  | 
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| 21 | |||
| 22 | /**  | 
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| 23 | * The url which is used to load local resources.  | 
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| 24 | * @var string  | 
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| 25 | * @since 2.0.0  | 
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| 26 | */  | 
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| 27 | protected static $url = '';  | 
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| 28 | |||
| 29 | /**  | 
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| 30 | * Utility method that attempts to get an attachment's ID by it's url  | 
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| 31 | * @since 1.0.0  | 
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| 32 | * @param string $img_url Attachment url  | 
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| 33 | * @return int|false Attachment ID or false  | 
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| 34 | */  | 
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| 35 | 1 | 	public static function image_id_from_url( $img_url ) { | 
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| 77 | |||
| 78 | /**  | 
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| 79 | * Utility method that returns time string offset by timezone  | 
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| 80 | * @since 1.0.0  | 
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| 81 | * @param string $tzstring Time string  | 
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| 82 | * @return string Offset time string  | 
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| 83 | */  | 
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| 84 | 2 | 	public static function timezone_offset( $tzstring ) { | 
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| 104 | |||
| 105 | /**  | 
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| 106 | * Utility method that returns a timezone string representing the default timezone for the site.  | 
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| 107 | *  | 
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| 108 | 	 * Roughly copied from WordPress, as get_option('timezone_string') will return | 
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| 109 | * an empty string if no value has been set on the options page.  | 
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| 110 | * A timezone string is required by the wp_timezone_choice() used by the  | 
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| 111 | * select_timezone field.  | 
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| 112 | *  | 
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| 113 | * @since 1.0.0  | 
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| 114 | * @return string Timezone string  | 
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| 115 | */  | 
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| 116 | 1 | 	public static function timezone_string() { | 
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| 117 | 1 | $current_offset = get_option( 'gmt_offset' );  | 
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| 118 | 1 | $tzstring = get_option( 'timezone_string' );  | 
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| 119 | |||
| 120 | // Remove old Etc mappings. Fallback to gmt_offset.  | 
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| 121 | 1 | 		if ( false !== strpos( $tzstring, 'Etc/GMT' ) ) { | 
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| 122 | $tzstring = '';  | 
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| 123 | }  | 
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| 124 | |||
| 125 | 1 | 		if ( empty( $tzstring ) ) { // Create a UTC+- zone if no timezone string exists | 
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| 126 | 1 | 			if ( 0 == $current_offset ) { | 
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| 127 | 1 | $tzstring = 'UTC+0';  | 
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| 128 | 1 | 			} elseif ( $current_offset < 0 ) { | 
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| 129 | $tzstring = 'UTC' . $current_offset;  | 
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| 130 | 			} else { | 
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| 131 | $tzstring = 'UTC+' . $current_offset;  | 
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| 132 | }  | 
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| 133 | 1 | }  | 
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| 134 | |||
| 135 | 1 | return $tzstring;  | 
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| 136 | }  | 
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| 137 | |||
| 138 | /**  | 
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| 139 | * Returns a timestamp, first checking if value already is a timestamp.  | 
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| 140 | * @since 2.0.0  | 
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| 141 | * @param string|int $string Possible timestamp string  | 
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| 142 | * @return int Time stamp  | 
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| 143 | */  | 
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| 144 | 10 | 	public static function make_valid_time_stamp( $string ) { | 
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| 153 | |||
| 154 | /**  | 
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| 155 | * Determine if a value is a valid timestamp  | 
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| 156 | * @since 2.0.0  | 
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| 157 | * @param mixed $timestamp Value to check  | 
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| 158 | * @return boolean Whether value is a valid timestamp  | 
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| 159 | */  | 
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| 160 | 10 | 	public static function is_valid_time_stamp( $timestamp ) { | 
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| 165 | |||
| 166 | /**  | 
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| 167 | * Checks if a value is 'empty'. Still accepts 0.  | 
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| 168 | * @since 2.0.0  | 
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| 169 | * @param mixed $value Value to check  | 
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| 170 | * @return bool True or false  | 
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| 171 | */  | 
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| 172 | 58 | 	public static function isempty( $value ) { | 
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| 175 | |||
| 176 | /**  | 
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| 177 | * Checks if a value is not 'empty'. 0 doesn't count as empty.  | 
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| 178 | * @since 2.2.2  | 
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| 179 | * @param mixed $value Value to check  | 
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| 180 | * @return bool True or false  | 
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| 181 | */  | 
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| 182 | 3 | 	public static function notempty( $value ){ | 
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| 183 | 3 | return null !== $value && '' !== $value && false !== $value;  | 
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| 184 | }  | 
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| 185 | |||
| 186 | /**  | 
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| 187 | * Filters out empty values (not including 0).  | 
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| 188 | * @since 2.2.2  | 
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| 189 | * @param mixed $value Value to check  | 
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| 190 | * @return bool True or false  | 
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| 191 | */  | 
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| 192 | 2 | 	public static function filter_empty( $value ) { | 
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| 193 | 2 | return array_filter( $value, array( __CLASS__, 'notempty' ) );  | 
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| 194 | }  | 
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| 195 | |||
| 196 | /**  | 
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| 197 | * Insert a single array item inside another array at a set position  | 
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| 198 | * @since 2.0.2  | 
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| 199 | * @param array &$array Array to modify. Is passed by reference, and no return is needed.  | 
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| 200 | * @param array $new New array to insert  | 
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| 201 | * @param int $position Position in the main array to insert the new array  | 
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| 202 | */  | 
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| 203 | 2 | 	public static function array_insert( &$array, $new, $position ) { | 
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| 208 | |||
| 209 | /**  | 
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| 210 | * Defines the url which is used to load local resources.  | 
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| 211 | * This may need to be filtered for local Window installations.  | 
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| 212 | * If resources do not load, please check the wiki for details.  | 
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| 213 | * @since 1.0.1  | 
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| 214 | * @return string URL to CMB2 resources  | 
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| 215 | */  | 
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| 216 | 2 | 	public static function url( $path = '' ) { | 
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| 217 | 2 | 		if ( self::$url ) { | 
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| 218 | 1 | return self::$url . $path;  | 
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| 219 | }  | 
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| 220 | |||
| 221 | 1 | $cmb2_url = self::get_url_from_dir( cmb2_dir() );  | 
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| 222 | |||
| 223 | /**  | 
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| 224 | * Filter the CMB location url  | 
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| 225 | *  | 
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| 226 | * @param string $cmb2_url Currently registered url  | 
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| 227 | */  | 
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| 228 | 1 | self::$url = trailingslashit( apply_filters( 'cmb2_meta_box_url', $cmb2_url, CMB2_VERSION ) );  | 
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| 229 | |||
| 230 | 1 | return self::$url . $path;  | 
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| 231 | }  | 
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| 232 | |||
| 233 | /**  | 
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| 234 | * Converts a system path to a URL  | 
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| 235 | * @since 2.2.2  | 
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| 236 | * @param string $dir Directory path to convert.  | 
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| 237 | * @return string Converted URL.  | 
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| 238 | */  | 
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| 239 | 2 | 	public static function get_url_from_dir( $dir ) { | 
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| 240 | 2 | $dir = self::normalize_path( $dir );  | 
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| 241 | |||
| 242 | // Let's test if We are in the plugins or mu-plugins dir.  | 
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| 243 | 2 | $test_dir = trailingslashit( $dir ) . 'unneeded.php';  | 
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| 244 | if (  | 
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| 245 | 2 | 0 === strpos( $test_dir, self::normalize_path( WPMU_PLUGIN_DIR ) )  | 
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| 246 | 2 | || 0 === strpos( $test_dir, self::normalize_path( WP_PLUGIN_DIR ) )  | 
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| 247 | 2 | 		) { | 
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| 248 | // Ok, then use plugins_url, as it is more reliable.  | 
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| 249 | 1 | return trailingslashit( plugins_url( '', $test_dir ) );  | 
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| 250 | }  | 
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| 251 | |||
| 252 | // Ok, now let's test if we are in the theme dir.  | 
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| 253 | 2 | $theme_root = self::normalize_path( get_theme_root() );  | 
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| 254 | 2 | 		if ( 0 === strpos( $dir, $theme_root ) ) { | 
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| 255 | // Ok, then use get_theme_root_uri.  | 
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| 256 | 1 | return set_url_scheme(  | 
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| 257 | 1 | trailingslashit(  | 
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| 258 | 1 | str_replace(  | 
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| 259 | 1 | untrailingslashit( $theme_root ),  | 
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| 260 | 1 | untrailingslashit( get_theme_root_uri() ),  | 
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| 261 | $dir  | 
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| 262 | 1 | )  | 
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| 263 | 1 | )  | 
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| 264 | 1 | );  | 
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| 265 | }  | 
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| 266 | |||
| 267 | // Check to see if it's anywhere in the root directory  | 
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| 268 | |||
| 269 | 2 | $site_dir = self::normalize_path( self::$ABSPATH );  | 
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| 270 | 2 | $site_url = trailingslashit( is_multisite() ? network_site_url() : site_url() );  | 
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| 271 | |||
| 272 | 2 | $url = str_replace(  | 
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| 273 | 2 | array( $site_dir, WP_PLUGIN_DIR ),  | 
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| 274 | 2 | array( $site_url, WP_PLUGIN_URL ),  | 
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| 275 | $dir  | 
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| 276 | 2 | );  | 
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| 277 | |||
| 278 | 2 | return set_url_scheme( $url );  | 
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| 279 | }  | 
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| 280 | |||
| 281 | /**  | 
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| 282 | * `wp_normalize_path` wrapper for back-compat. Normalize a filesystem path.  | 
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| 283 | *  | 
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| 284 | * On windows systems, replaces backslashes with forward slashes  | 
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| 285 | * and forces upper-case drive letters.  | 
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| 286 | * Allows for two leading slashes for Windows network shares, but  | 
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| 287 | * ensures that all other duplicate slashes are reduced to a single.  | 
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| 288 | *  | 
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| 289 | * @since 2.2.0  | 
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| 290 | *  | 
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| 291 | * @param string $path Path to normalize.  | 
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| 292 | * @return string Normalized path.  | 
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| 293 | */  | 
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| 294 | 2 | 	protected static function normalize_path( $path ) { | 
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| 295 | 2 | 		if ( function_exists( 'wp_normalize_path' ) ) { | 
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| 296 | return wp_normalize_path( $path );  | 
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| 297 | }  | 
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| 298 | |||
| 299 | // Replace newer WP's version of wp_normalize_path.  | 
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| 300 | 2 | $path = str_replace( '\\', '/', $path );  | 
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| 301 | 2 | $path = preg_replace( '|(?<=.)/+|', '/', $path );  | 
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| 302 | 2 | 		if ( ':' === substr( $path, 1, 1 ) ) { | 
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| 303 | 1 | $path = ucfirst( $path );  | 
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| 304 | 1 | }  | 
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| 305 | |||
| 306 | 2 | return $path;  | 
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| 307 | }  | 
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| 308 | |||
| 309 | /**  | 
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| 310 | * Get timestamp from text date  | 
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| 311 | * @since 2.2.0  | 
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| 312 | * @param string $value Date value  | 
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| 313 | * @param string $date_format Expected date format  | 
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| 314 | * @return mixed Unix timestamp representing the date.  | 
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| 315 | */  | 
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| 316 | 	public static function get_timestamp_from_value( $value, $date_format ) { | 
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| 317 | $date_object = date_create_from_format( $date_format, $value );  | 
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| 318 | return $date_object ? $date_object->setTime( 0, 0, 0 )->getTimeStamp() : strtotime( $value );  | 
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| 319 | }  | 
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| 320 | |||
| 321 | /**  | 
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| 322 | * Takes a php date() format string and returns a string formatted to suit for the date/time pickers  | 
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| 323 | * It will work with only with the following subset ot date() options:  | 
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| 324 | *  | 
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| 325 | * d, j, z, m, n, y, and Y.  | 
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| 326 | *  | 
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| 327 | * A slight effort is made to deal with escaped characters.  | 
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| 328 | *  | 
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| 329 | * Other options are ignored, because they would either bring compatibility problems between PHP and JS, or  | 
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| 330 | * bring even more translation troubles.  | 
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| 331 | *  | 
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| 332 | * @since 2.2.0  | 
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| 333 | * @param string $format php date format  | 
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| 334 | * @return string reformatted string  | 
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| 335 | */  | 
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| 336 | 5 | 	public static function php_to_js_dateformat( $format ) { | 
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| 337 | |||
| 338 | // order is relevant here, since the replacement will be done sequentially.  | 
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| 339 | $supported_options = array(  | 
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| 340 | 5 | 'd' => 'dd', // Day, leading 0  | 
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| 341 | 5 | 'j' => 'd', // Day, no 0  | 
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| 342 | 5 | 'z' => 'o', // Day of the year, no leading zeroes,  | 
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| 343 | // 'D' => 'D', // Day name short, not sure how it'll work with translations  | 
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| 344 | // 'l' => 'DD', // Day name full, idem before  | 
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| 345 | 5 | 'm' => 'mm', // Month of the year, leading 0  | 
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| 346 | 5 | 'n' => 'm', // Month of the year, no leading 0  | 
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| 347 | // 'M' => 'M', // Month, Short name  | 
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| 348 | // 'F' => 'MM', // Month, full name,  | 
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| 349 | 5 | 'y' => 'y', // Year, two digit  | 
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| 350 | 5 | 'Y' => 'yy', // Year, full  | 
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| 351 | 5 | 'H' => 'HH', // Hour with leading 0 (24 hour)  | 
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| 352 | 5 | 'G' => 'H', // Hour with no leading 0 (24 hour)  | 
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| 353 | 5 | 'h' => 'hh', // Hour with leading 0 (12 hour)  | 
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| 354 | 5 | 'g' => 'h', // Hour with no leading 0 (12 hour),  | 
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| 355 | 5 | 'i' => 'mm', // Minute with leading 0,  | 
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| 356 | 5 | 's' => 'ss', // Second with leading 0,  | 
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| 357 | 5 | 'a' => 'tt', // am/pm  | 
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| 358 | 'A' => 'TT' // AM/PM  | 
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| 359 | 5 | );  | 
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| 360 | |||
| 361 | 5 | 		foreach ( $supported_options as $php => $js ) { | 
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| 362 | // replaces every instance of a supported option, but skips escaped characters  | 
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| 363 | 5 | $format = preg_replace( "~(?<!\\\\)$php~", $js, $format );  | 
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| 364 | 5 | }  | 
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| 365 | |||
| 366 | 5 | $format = preg_replace_callback( '~(?:\\\.)+~', array( __CLASS__, 'wrap_escaped_chars' ), $format );  | 
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| 367 | |||
| 368 | 5 | return $format;  | 
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| 369 | }  | 
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| 370 | |||
| 371 | /**  | 
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| 372 | * Helper function for CMB_Utils->php_to_js_dateformat, because php 5.2 was retarded.  | 
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| 373 | * @since 2.2.0  | 
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| 374 | * @param $value Value to wrap/escape  | 
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| 375 | * @return string Modified value  | 
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| 376 | */  | 
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| 377 | 4 | 	public static function wrap_escaped_chars( $value ) { | 
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| 380 | |||
| 381 | /**  | 
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| 382 | * Send to debug.log if WP_DEBUG is defined and true  | 
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| 383 | *  | 
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| 384 | * @since 2.2.0  | 
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| 385 | *  | 
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| 386 | * @param string $function Function name  | 
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| 387 | * @param int $line Line number  | 
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| 388 | * @param mixed $msg Message to output  | 
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| 389 | * @param mixed $debug Variable to print_r  | 
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| 390 | */  | 
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| 391 | 	public static function log_if_debug( $function, $line, $msg, $debug = null ) { | 
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| 396 | |||
| 397 | /**  | 
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| 398 | * Determine a file's extension  | 
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| 399 | * @since 1.0.0  | 
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| 400 | * @param string $file File url  | 
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| 401 | * @return string|false File extension or false  | 
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| 402 | */  | 
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| 403 | 6 | 	public static function get_file_ext( $file ) { | 
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| 407 | |||
| 408 | /**  | 
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| 409 | * Get the file name from a url  | 
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| 410 | * @since 2.0.0  | 
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| 411 | * @param string $value File url or path  | 
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| 412 | * @return string File name  | 
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| 413 | */  | 
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| 414 | 5 | 	public static function get_file_name_from_path( $value ) { | 
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| 418 | |||
| 419 | /**  | 
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| 420 | * Check if WP version is at least $version.  | 
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| 421 | * @since 2.2.2  | 
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| 422 | * @param string $version WP version string to compare.  | 
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| 423 | * @return bool Result of comparison check.  | 
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| 424 | */  | 
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| 425 | 6 | 	public static function wp_at_least( $version ) { | 
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| 428 | |||
| 429 | /**  | 
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| 430 | * Combines attributes into a string for a form element.  | 
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| 431 | * @since 1.1.0  | 
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| 432 | * @param array $attrs Attributes to concatenate.  | 
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| 433 | * @param array $attr_exclude Attributes that should NOT be concatenated.  | 
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| 434 | * @return string String of attributes for form element.  | 
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| 435 | */  | 
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| 436 | 45 | 	public static function concat_attrs( $attrs, $attr_exclude = array() ) { | 
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| 450 | |||
| 451 | /**  | 
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| 452 | * Ensures value is an array.  | 
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| 453 | *  | 
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| 454 | * @since 2.2.4  | 
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| 455 | *  | 
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| 456 | * @param mixed $value Value to ensure is array.  | 
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| 457 | * @param array $default Default array. Defaults to empty array.  | 
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| 458 | *  | 
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| 459 | * @return array The array.  | 
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| 460 | */  | 
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| 461 | 	public static function ensure_array( $value, $default = array() ) { | 
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| 477 | |||
| 478 | }  | 
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| 479 | 
You can fix this by adding a namespace to your class:
When choosing a vendor namespace, try to pick something that is not too generic to avoid conflicts with other libraries.